If you see the status listed as "cancelled" on a subscription in your subscriber summary that means that this customer has turned off their auto renewal for their monthly paid subscription to your page so they will not continue to be billed for their subscription. It does not mean that the customer has been refunded or that they have "charged back" their subscription, only that they have turned off the auto renew so they will not be billed for subsequent months of access to your page. You can find out common cancellation reasons on your "stats" page at the bottom of the page under "Cancellation Reasons."
If you see the status of "expired" on a subscription, it means their rebill wasn't successful. Possibly their card was declined, or they have to add more cryptocurrency to their account balance.